Antifelting process for keratinous materials



ra es 4 14 Claims. (Cl. 8-127.6)

In application Ser. No. 152,640 there is described a process for preventing the shrinking and felting of keratinous materials such as hair and wool in which superior results are attained by the use of aqueous solutions of alkali metal salts of dichloroisocyanuric acid. This invention is an improvement on that novel process.

The process of the prior application imparts to keratinous materials, especially to fibers, an excellent resistance to felting and shrinking but it is advisable to maintain an excess of active chlorine in the bath, only a part of the active chlorine being consumed during the course of treatment, the solution being enriched with the salts before being used again for a new treatment. That process was satisfactory in many cases but in certain cases that manner of operation proved to be confining because it required a strict control of the concentration of the bath, which was maintained by frequent analysis of the bath for active chlorine, in order that the keratinous material should be removed at the moment when the consumption of active chlorine indicated adequate treatment. Furthermore the treatment with the alkali salts of dichloroisocyanuric acid was followed by dechlorin'ation and rinsing, which required either that the material be transported to another piece of apparatus for these steps, or the removal of the antifelting solution to reservoirs and the substitution of the dechlorinating and rinsing solutions. That technique required apparatus beyond those which have generally been provided for other processes used in the textile industry, or to use several apparatus for a single treatment. The latter technique caused a mobilization of apparatus, and required manipulation for the antifelting treatment and those which followed it.

It is an object of this invention to improve the operation, especially the evenness and completeness of exhaust, of antifelting and antishrinking solutions of which the active agent is a metal salt of dichloroisocyanuric acid. Another object is to improve the appearance of the keratinous product and to prevent the slight yellowing which sometimes attends the use of such baths. Another object is to simplify the handling of solutions and of the keratinous materials during the treatment proper and the dechlorination and washing steps which follow. Another object is to increase the activity of such baths, or preferably to reduce their concentration while maintaining effective and rapid action, and to eliminate the use of an excess of chlorine. A novel product of the invention is a keratinous object, for instance wool fibers, of better color than the original before treatment, clearer and as though a degree of bleaching had occurred.

The objects of the invention are accomplished generally speaking by a method of preventing the felting and shrinking of keratinous materials which comprises soaking the keratinous material with an aqueous solution of an alkali metal salt of dichloroisocyanuric acid and a metal permanganate at neutral to alkaline pH, and by a solution for the prevention of felting and shrinking in keratinous materials consisting in its essential elements of water, an alkali metal salt of N,N-dichloroisocyanuric acid, and an alkali metal permanganate.

According to the invention the antifelting and antishrinking treatment of the keratinous fibers is carried out in an aqueous bath containing the alkali metal salts of N- 3,397,942 Patented Aug. 20, 1968 dichloroisocyanuric acid, and preferably, potassium permanganate at a pH about neutral, or from about pH 6 to about pH 9. One does not go beyond the scope of the invention by using soluble permanganates of other alkali metals, alkali earth metals or the like but in practice potassium permanganate is very effective, considerably cheaper, and simpler to use than many of such substituents.

In order to maintain the pH in the stated range no addition is ordinarily necessary but if it is desired to operate at pH 8 and 9 alkaline agents may be added, for instance borax and sodium pyrophosphate.

In a preferred mode of procedure aqueous solutions are used which have a concentration of the alkali metal salts of dichloroisocyanuric acid which is such that the quantity of active chlorine, expressed as a weight ratio to the weight of the keratinous material, is between about 1% and about 5%, and in which the concentration of alkali permanganate, similarly expressed, is between about 0.5% and about 2.5%.

According to a modification of the process the treatment of textile materials is carried out at pHs about 8 by addition of an alkaline agent as aforesaid. The weight ratio between the textile materials treated and the bath is preferably between about 1/5 and about 1/60. Good results both with respect to antifelting and with respect to the percentage of shrinkage is obtained under these circumstances, in a time which may vary between about 20 and minutes. The process is carried out at room temperature, preferably, but may vary from about 5 to about 35 C. without harmful results.

In some cases it may be advantageous to add to the working bath a surface active agent which performs the function of assisting the penetration of the material by the bath. For this purpose it is possible to use surface active agents of anionic, nonionic, and cationic type, choosing from the numerous well known agents of these types those which are stable in the solution of the present case. These agents should not have any influence on the stability of the treating solutions and should not attack the keratinous material. Among satisfactory agents are, for example, the condensates of ethylene oxide and lauric alcohol, and condensates of ethylene oxide on alcohols which are obtained by the process which is called the 'oxo process by practitioners of the art. The oxo process generally consists in reacting olefins with carbon oxide and hydrogen, which produces alcohols with mixed chains and in some cases mixtures of primary and secondary alcohols which have the same characteristics.

The antifelting treatment is normally completed by dechlorination and rinsing. The dechlorination simultaneously eliminates manganese dioxide which has been deposited on the fibers. For this purpose one may use aqueous solutions of sodium bisulfite, sodium hydrosulfite, and sodium metasulfite, which are preferred but which are merely illustrative of many dechlorinating agents which are currently used in the textile industry and 'which are useful in some degree.

The invention is capable of successful application to all types of keratinous materials such as hair, combed or carded wool, filaments, sheets, knitwear, and clothing, to give examples.

The addition of the permanganate to the bath improves the activity of the alkali metal salts of dichloroisocyanuric acid with respect to keratinous fibers and this increased activity confers excellent nonfelting and nonshrinking characteristics upon them with less concentrated solutions, of which the concentration in active chlorine is little or nothing at the end of the treatment, amounting to complete exhaustion of the bath. This gives an advantage in simplicity of application and manipulation. It is not necessary to test the quantity of salts which ottiiibifi iiUid have been consumed or to recover them, or to readjust the concentration of the bath for reuse.

The use of the less concentrated solutions provided by this process has the advantage of providing a more regular application and an improved product. Another ad vantage of these mixed baths containing permanganates resides in the fact that after treatment there is no observable yellowing of the keratinous material and in certain cases there has been a definite and observable clarification of the material as though a mild bleaching had occurred.

The following examples are given solely for the purpose of illustration and without limiting the generality of what is elsewhere herein stated:

The tests were carried out on ribbons of combed wool weighting at 45 m./ kg., derived from Australia, quality 100/105, mean diameter 21.55 microns; and upon hanks of combed wool Nm 1/28, merinos quality, undyed, degreased.

The measurement of shrinkage represents both itself and the antifelting characteristics of the material, so the tests of treated and untreated material were carried out in the following way to determine the shrinkage of the material Without and with the novel treatment. In making these tests on the ribbon, two threads were sewed across a ribbon and at each quarter of the distance therebetween. The distance between the extremities was 21 cm. After preparation of the test pieces, the measurement being made under a tension of 100 grams, the test pieces were subjected to fulling by immersing'them in a 1,000 cc. receptacle containing rubber balls and 150 cc. of a solution containing 5 g./l. of soap, 0.5 g./l. of sodium carbonate, and 2 cc./l. of a silicone type antifrothing agent; such agents are well known. The receptacle was attached to a wheel rotating 44 rpm. in a water bath at 40 C. for minutes. After the test the test piece was rinsed and dried in the free air without tension; afterward, it was again measured under the 100 grams tension. The percent of shrinkage was determined by the formula Example 1 A ribbon as described above was treated for 60 minutes at room temperature with an aqueous solution containing 2% of chlorine derived from the sodium salt of dichloroisocyanuric acid, 2% of the potassium permanganate, and 1 g./l. of a surface tension reducing agent being the condensation product of 9 moles of ethylene oxide with 1 mole of lauric alcohol, at pH 6.65.

The weight of the textile material to the weight of the bath was 1/ 13. After this treatment the test pieces were dechlorinated in a 7.5%1 solution of 36 B. bisulfite of sodium and rinsed. An identical sample, and the sample from this treatment, were subjected to fulling prior to dechlorination as aforesaid, under identical conditions. After the fulling the untreated test piece had shrunk 54% and the test piece which had undergone the treatment of this invention only 15 When the banks Nm 2/28 were treated in the same way they showed a shrinkage of 2.8% for the material treated according to Example 1 and 55% for the untreated material.

The treated material had a-very good hand and a slight effect of bleaching was observed.

Example 2 Test pieces similar to the above were treated for 45 minutes at room temperature in an aqueous solution containing 2% of active chlorine furnished by sodium dichloroisocyanurate, 2% of potassium permanganate, 1 g./l. of a surface tension reducing agent, at pH 6.65. The treatment was similar to that of Example 1, except that the weight of the textile material to the weight of the bath was 1/6. After this treatment the test pieces were dechlorinated in a 5.0% solution of 36 B. bisul- -fite of sodium and rinsed. The untreated test piece shrank 42% and the treated test piece only 4.8%. The material had a good hand and exhibited a slight degree of whitening.

Example 3 A similar test was carried out with an aqueous solution containing 3% of active chlorine furnished by sodium N,N-dichloroisocyanurate, 2% of potassium permanganate, and 1 g./l. of the surface tension reducing agent of Example 1. The pH was 6.65. The weight of the keratinous material to the weight of the bath was 1/ 30. Dechlorination after treatment was by means of an aqueous solution of 10% sodium bisulfite of 36 B. The test pieces were rinsed and subjected to fulling and tested for shrinkage. The untreated test piece shrank 46.6% and the treated wool shrank 2.4%. The whitening of the wool was very noticeable and the wool had an excellent hand.

For dechlorination aqueous solution of sodium bisulfite, sodium metasulfite, and sodium hydrosulfite are customarily used and are thoroughly satisfactory, but does not prevent one from using other known dechlorinating agents if one desires. In the earlier case, which has been identified, the concentrations of active chlorine were substantially higher than those which are employed in the present invention because of the relatively mild activity of such baths on the fiber, an excess of active chlorine being required to increase the activity and speed of the bath.

In the presence of potassium permanganate the reactivity of such baths was materially increased, the exhaustion of the bath was more complete for a given content of chlorine, and it was thus possible to reduce the content of the active agent in the bath, to exhaust the bath more completely and to discard it after use. The antifelting power of the bath has been materially increased by the present invention. This improvement is the result of the joint effect of the alkali metal salts of dichloroisocyanuric acid and potassium permanganate in the bath. Observation has detected the existence of synergistic effect. The expression Nm 1/28 means that the thread is composed of one strand measuring 28 km. to the kilogram, thus Nm 2/16 means that the thread is composed of 2 strands of which each measures 16 km. to the kilogram.

The advantages of the invention are the accomplishment of each of the objects as stated above; the concentration of active chlorine provided 'by the salts in the bath has been reduced to about half of that which was previously needed for a like result; the bath exhausts more evenly and more completely; the resistance, to felting and shrinking, of the keratinous materials has been increased; the yellowing of the product has been ended and the product issues from the treatment with better appearance and as clear as though slightly bleached; the strict control of the process previously required in some cases has been relaxed; the apparatus has been simplified and the handling of materials and solutions has been reduced.

As many apparently widely different embodiments of the present invention may be made without departing from the spirit and scope thereof, it is to be understood that the invention is not limited to the specific embodiments.

What is claimed is:

1. A method of preventing the felting and shrinking of keratinous materials which comprises soaking the keratinous material with an aqueous solution of an alkali metal salt of dichloroisocyanuric acid and a metal per manganate at neutral to alkaline pH.

2. A method according to claim 1 in which the metal of the permanganate is an alkali metal.

3. A method according to claim 1 in which the metal of the permanganate is potassium.

4. A method according to claim 3 in which the alkali metal salt in the solution provides between about 1 and about 5 of active chlorine percent weight of keratinous material, and the potassium permanganate in the solution is between about 0.5 and about 2.5% of the said weight.

5. A method according to claim 1 in which the ratio of the weight of the keratinous material to the weight of the bath is between about 1/5 and about l/ 60.

6. A method according to claim 1 in which the pH of the treating solution is between about 6 and about 9.

7. A method according to claim 1 in which the treat-v ment is between about 20 and about 90 minutes, after which the keratinous material is rinsed, dechlorinated, and dried.

8. A method according to claim 1 in which the temperature of the solution is kept between about 5 C. and about 35 C. during the treatment.

9. A method according to claim 1 in which the bath also contains a surface active agent.

10. A solution for the prevention of felting and shrinking in keratinous materials consisting in its essential elements of water, an alkali metal salt of N,N-dichloroisocyanuric acid, and an alkali metal permanganate.

11. An aqueous solution for preventing the felting and shrinking of keratinous materials comprising an alkali metal salt of N,N-dichloroisocyanuric acid, an alkali metal permanganate, and a surface active agent, at a pH between about 6 and about 9, and at about room temperature.

12. An aqueous solution according to claim 11 in which the alkali metal of the salt of N,N-dichloroisocyanuric acid is sodium and the alkali metal of the permanganate is potassium.

13. A method of preventing the felting and shrinking of keratinous materials which comprises soaking the keratinous material in an aqueous bath at a pH between about 6 and about 9 containing a quantity of an alkali metal salt of N,N-dichloroisocyanuric acid which provides between about 1 and about 5 parts of active chlorine percent Weight of the keratinous material, and an alkali metal permanganate in a quantity between about 0.5 and about 2.5 percent weight of the keratinous material, the weight of keratinous material to the weight of the bath being between about 1/5 and 1/ 60, or a period between about 20 and about minutes, and rinsing and dechlorinating the treated material.

14. The method of claim 13 in which the alkali metal of the acid salt is sodium and the alkali metal of the permanganate is potassium.

References Cited STATES PATENTS NORMAN G. TORCHIN, Primary Examiner.

J. C. CANNON, Assistant Examiner. 

1. A METHOD OF PREVENTING THE FELTING AND SHRINKING OF KERATINOUS MATERIALS WHICH COMPRISES SOAKING AND THE KERATINOUS MATERIAL WITH AN AQUEOUS SOLUTION OF AN ALALI METAL SALT OF DICHLOROLSOCYANURIC ACID AND A METAL PERMANGANATE AT NEUTRAL TO ALKALINE PH. 